Numbers Chapter 10

10:2
Make thee two trumpets of silver; of a whole piece shalt thou make them: that thou mayest use them for the calling of the assembly, and for the journeying of the camps.

10:9-10
And if ye go to war in your land against the enemy that oppresseth you, then ye shall blow an alarm with the trumpets; and ye shall be remembered before the Lord your God, and ye shall be saved from your enemies.
Also in the day of your gladness, and in your solemn days, and in the beginnings of your months, ye shall blow with the trumpets over your burnt offerings, and over the sacrifices of your peace offerings; that they may be to you for a memorial before your God: I am the Lord your God.

10:35-36
And it came to pass, when the ark set forward, that Moses said, Rise up, Lord, and let thine enemies be scattered; and let them that hate thee flee before thee.
And when it rested, he said, Return, O Lord, unto the many thousands of Israel.